Plate fin heat exchangers generally consist of a core formed of a plurality of stacked layers. Each layer has a plurality of continuously corrugated or finned elements that are arranged to form a plurality of channels. The channels in one layer may lie in transverse or parallel relation to the channels formed in adjacent layers. A parting sheet separates the adjacent layers. Fluids having differing amounts of heat energy flow through the channels of adjacent layers so that heat energy may be transferred from fluid to fluid.
Environmental control systems (“ECS”) that utilize air cycle machines are well known. ECS systems generally control the temperature and humidity of air within an enclosed environment, such as an aircraft cabin, and usually include a compressor for pressurizing air input thereto, and a turbine for expanding and cooling the air. Some turbines are capable of delivering air at temperatures as low as 100° F. below zero.
At such cold temperatures moisture within the air may be precipitated out in the form of snow or ice. The ice and snow may clog and shut down any downstream components such as heat exchangers. If a heat exchanger becomes clogged, heat transfer among the fluids flowing therethrough may be severely reduced. The air from the turbine may not warm to usable levels for cabins and the fluid that warms the air from the ECS may not be cooled enough for effective downstream use.